This proposed project is a resubmission of the PI's first R01 application. Alcohol-dependent individuals have well-described disturbances of sleep, but whether these sleep disturbances precede or follow heavy, problem drinking is unknown. Several lines of evidence across the human life span now suggest that sleep disturbances may precede and represent a marker of risk for the development of alcohol use disorders. For instance, there appears to be a longitudinal relationship between sleep problems, alcohol use, and alcohol use disorders in both adolescents and adults. Very few studies, however, have systematically examined the sleep patterns, habits, and architecture of biological children of an alcohol- dependent parent (COAs), who already are at increased risk both to drink earlier than their peers and to have an early onset of alcohol use disorders. A longitudinal investigation of sleep parameters in relation to risk for early onset of alcohol use and alcohol related problems among COAs and controls (non-COAs) would clarify the influence of sleep disturbances and potentially inform prevention and early intervention efforts. The current proposal seeks funding to support a longitudinal study on sleep patterns, architecture, and regulation in COAs and controls. Specific aims are: (i) to examine the sleep patterns, habits, and architecture of COAs and controls over time via multiple measures of sleep, including self-report, parental ratings, actigraphy, and polysomnography; (ii) to understand the effects of sleep disturbances on neurocognitive functions, behavioral problems, and risk for early alcohol use/abuse among COAs and controls; and (iii) to understand how gender, pubertal development, and perceived stress may moderate the relationship between sleep problems and alcohol use/abuse among COAs and controls. A three-wave longitudinal design is proposed. Participants will be 8-12 years old at Time 1, 9-13 years old at Time 2, and 10-14 years old at Time 3. Multiple measures of sleep, including actigraphy and polysomnography data will be collected at Time 1. At Times 2 and 3, actigraphy will be repeated and data on self-report and parental ratings of sleep, as well as neurocognitive functions and behavioral problems will be gathered. Information regarding onset of alcohol and other drug use, as well as related problems will also be collected at Times 2 and 3. This project has the potential to document the relationships among sleep problems, family history of alcoholism, neurocognitive functions, behavioral problems, and the development of alcohol problems among COAs and controls. Results of the study will lead to practical information on the relationship between sleep problems and alcohol use disorders, with implications for prevention and early intervention.